Prosthetic or orthotic knee joints replace or support the function of a natural knee joint. In order to achieve a maximum optimal functionality of the artificial knee joint, there are a multiplicity of designs on the market, which influence the behavior of the knee joints during the standing phase and the swing phase. Mechatronic knee joints are known, in which the movement situations are detected by means of a plurality of different sensors and, on the basis of the sensor data, a resistance device, by means of which the bending resistance (also referred to as flexion resistance) or the extension resistance is varied, is controlled. One basic problem is that the great variety of the possible movement situations can be encompassed only with difficulty in simple rules. In order to control actuators and brakes, therefore, so-called state machines are used, which are highly complex and represent many different activities. Disadvantages with this are the long development time and the use of elaborate components.
EP 1 237 513 B1 relates to a supporting device which replaces the existence or function of a limb and consists of at least two parts, connected to one another by an artificial joint, and a control device. The supporting device comprises a sensor, which detects an inclination angle relative to a line of gravity of a part connected to the joint and is coupled to the control device. The control device is arranged in such a way that it influences the joint on the basis of inclination angle data communicated by the sensor. In one configuration, the inclination angle sensor is arranged as a prosthetic knee joint on a thigh tube; in order to enhance the data situation, a second sensor may be arranged on the lower leg.
DE 10 2008 027 639 A1 relates to an orthotic joint for supporting an anatomical knee joint, having an upper joint part and a lower joint part which are connected to one another in an articulated fashion. A locking element for automatically unblocking and blocking the orthotic joint in an arbitrary position is provided, as is an actuation element for the locking element and a sensor means for detecting relevant information for the unblocking and blocking. An evaluation unit for evaluating the information acquired, and for forwarding this information to a control and/or regulating unit for the actuation element, is likewise provided. The sensor means comprises at least two sensors from the group: inclination sensors, rotation angle sensors, acceleration sensors or gyroscopes, for acquiring information describing the movement state and/or resting state of a person. Two sensors of one type or one sensor each of different types may be selected. All the sensors are arranged downward of the anatomical joint, in particular the knee joint.